I’ve been thinking about taking my tools to the next level of sophistication for a while now. Below I will try to present what I am creating and what I would like to achieve. I hope there will be some experts here who can give me some suggestions on what path to take.

Brief explanation on what I’m developing right now:
In the niche I cover, there is a need for tools that enable data collection, processing and presentation. So far, I use very simple technologies, accessible to many users, these are Excel, Outlook, Sharepoint. All this surrounded by my tools, which I prepare in VBA language. Mostly it works like this: someone prepares data on a form that I have prepared beforehand, which is then emailed to the person who collects the data and aggregates it into the main Excel tool, using extensive functions in VBA. This solution is finding its audience and so far they are satisfied because it meets their expectations.

Context:
Since I know the basics of several programming languages and have begun to delve more and more into the topics of desktop application development, I would like to replace the current solutions, with more modern ones. I have already started developing tools in C#, using frameworks such as WPF and MVVM. This solution could replace VBA entirely.I also have a solid understanding of SQL databases (Mainly MySQL, SQLite) and their queries.

What I’m looking for:
Since I am a solo developer, I am looking for the least intrusive and simple ways to transfer data from the reporters to the main database. The database would be connected to the main application and data could be edited and read from there.

I consider all possibilities, while I am most interested in those that do not require hosting, server or cloud on my side.

Additional notes:

1. My tools are only made for Windows users.
2. Company in which I’m working is not related to IT.
3. Development and distribution should be easy to manage by a single developer.
4. I’m open to different technologies, languages etc.
5. As this tools concerns small to medium enterprises, please consider the limitations that may occur from the local IT departments requirements.
6. Lists with data to be reported by each reporting person should be able to be edited by the Client’s administrator (main user).
7. Main application will be probably handled by one person, some more would be interested in just the resoults. Users responsible for reporting at the same time would rarely exceed 2 or 3 at a time (Very little chance that more than one person at a time would be sending data to main db).

If something needs to be elaborated on then please let me know.

Thank you in advance for any ideas and suggestions!

SQLite – not the best solution for many users accesing database at the same time.
MySQL – requires server, maybe setting on-premises server would be a good idea? But can be easly handled by one developer?
Outlook (Email) – sending form (in CSV, Excel sheet or whatever) and aggregating it to the main tool is not the most appeling way to handle this. But perhaps the only simple one?
MS Forms – difficulty to edit the list with items to report.